This proposal seeks support to analyze data collected in the Women's Health and Aging Study II (WHAS II), a prospective, observational cohort study of non-disabled, older women to evaluate whether cognitive activity may exert downstream benefits on physical as well as cognitive functions to promote healthy aging. The specific aims are to: 1) evaluate the impact of cognitive activity on health and components of physical function, covarying for sociodemographic, health, and mobility factors; 2) evaluate those parameters of high and moderate intensity cognitive activity (frequency, breadth) associated with the maintenance of or decline in components of physical function, and; 3) to begin to develop a conceptual framework of how cognitive activity may directly mediate the reservation of physical functions, or whether it operates as a confound with other mediators, such as cognition or psychological well-being. Study participants are a population-based sample of 436 community-dwelling women who were 70-80 years of age at baseline and cognitively and physically high functioning in 1994-95. They have completed 3 comprehensive examinations, each 18 months apart, which include an extensive cognitive activity questionnaire and comprehensive assessment of cognition, physical function, and mental and physical health history. The WHAS II is now initiating a second 5-year wave of follow-up to assess the natural history of functional decline. Results obtained from this grant should propel and guide additional research on the role that cognitive activity may play in the decline or maintenance of physical functions in older women. If cognitive challenges in everyday life facilitate the maintenance of cognitive and physical abilities, they offer great potential for devising relatively inexpensive and benign interventions to reduce the risk of disability and dependency. Findings, either positive or negative, have implications for theories on the development of interventions to delay or prevent disability in aging adults. Innovative and cost-effective approaches to promoting physical and cognitive health are of growing importance as we confront the demographic and economic realities of an aging society.